====== Lymphatic drainage ======

The lymphatic [[drainage]] system of the [[brain]], composed of the [[glymphatic system]] and [[meningeal lymphatic vessel]]s (MLVs), plays an essential role in the clearance of [[toxic waste]] after [[brain injury]]. The neuroprotective effect of [[interleukin 33]] (IL-33) in TBI mice has been demonstrated; however, its impact on the brain [[lymphatic drainage]] is unclear.
Liu et al. established a [[fluid percussion injury model]] to examine the IL-33 administration effects on neurological function and [[lymphatic drainage]] in the acute brain of TBI [[mice]]. They verified that exogenous IL-33 could improve the motor and memory skills of TBI mice and demonstrated that in the acute phase, it increased the exchange of cerebrospinal and interstitial fluid, reversed the dysregulation and depolarization of [[aquaporin 4]] in the cortex and [[hippocampus]], improved the drainage of MLVs to deep cervical lymph nodes, and reduced tau accumulation and glial activation. 
Liu et al. speculated that the protective effect of exogenous IL-33 on TBI [[mice]]'s motor and [[cognitive function]]s is related to the enhancement of brain [[lymphatic drainage]] and toxic metabolite clearance from the [[cortex]] and [[hippocampus]] in the acute stage. These data further support the notion that IL-33 therapy may be an effective treatment strategy for alleviating acute [[brain injury]] after TBI.
((Liu M, Huang J, Liu T, Yuan J, Lv C, Sha Z, Wu C, Jiang W, Liu X, Nie M, Chen Y, Dong S, Qian Y, Gao C, Fan Y, Wu D, Jiang R. Exogenous interleukin 33 enhances the brain's lymphatic drainage and toxic protein clearance in acute traumatic brain injury mice. Acta Neuropathol Commun. 2023 Apr 7;11(1):61. doi: 10.1186/s40478-023-01555-4. PMID: 37024941.))

Using the model of the sound-induced opening of the BBB, Semyachkina-Glushkovskaya et al. clearly show how the brain clears [[dextran]] after it crosses the BBB via the meningeal lymphatic vessels. They first demonstrate the successful application of [[optical coherence tomography]] (OCT) for imaging of the lymphatic vessels in the meninges after the opening of the BBB, which might be a new useful strategy for noninvasive analysis of [[lymphatic drainage]] in daily clinical practice. Also, we give information about the depth and size of the meningeal lymphatic vessels in mice. These new fundamental data with the applied focus on the OCT shed light on the mechanisms of brain clearance and the role of lymphatic drainage in these processes that could serve as an informative platform for the development of therapy and diagnostics of diseases associated with injuries of the BBB such as stroke, brain trauma, glioma, depression, or Alzheimer disease
((Semyachkina-Glushkovskaya O, Abdurashitov A, Dubrovsky A, Bragin D, Bragina O,
Shushunova N, Maslyakova G, Navolokin N, Bucharskaya A, Tuchin V, Kurths J,
Shirokov A. Application of optical coherence tomography for in vivo monitoring of
the meningeal lymphatic vessels during opening of blood-brain barrier: mechanisms
of brain clearing. J Biomed Opt. 2017 Dec;22(12):1-9. doi:
10.1117/1.JBO.22.12.121719. PubMed PMID: 29275545.
)).